Bubble nucleation supersaturation, effect

The effect of NaCl on bubble nucleation in the presence of hydrophobic surfaces has also been examined. Excess nitrogen gas was dissolved in solution by equilibration under 25 atmospheres of pressure. Immediately following decompression the solution was supersaturated with nitrogen gas. In water and 0.02M NaCl, it was found that bubbles nucleated quickly (<25 sec) at a (hydrophobic) teflon surface. However, a 0.20M solution of NaCl was found to inhibit bubble formation. In ref>eat experiments, bubbles were found to form at the same sites on the hydrophobic surface. It would appear that the microstructure of the surface is important for the nucleation of bubbles. Microscopic surface cracks would present hydrophobic surfaces at very close separations, enabling nucleation to occur more readily. 

E.A. Hemmingsen, Effects of surfactants and electrolytes on the nucleation of bubbles in gas-supersaturated solutions, Z. Naturforsch. A33 (1978) 164-171. 

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